/*
 * Copyright (c) 2011 ARM Ltd
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the company may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>

/* The macro LONG_TEST controls whether a short or a more comprehensive test
   of strcmp should be performed.  */
#ifdef LONG_TEST
#ifndef BUFF_SIZE
#define BUFF_SIZE 1024
#endif

#ifndef MAX_BLOCK_SIZE
#define MAX_BLOCK_SIZE 128
#endif

#ifndef MAX_OFFSET
#define MAX_OFFSET 3
#endif

#ifndef MAX_DIFF
#define MAX_DIFF 8
#endif

#ifndef MAX_LEN
#define MAX_LEN 8
#endif

#ifndef MAX_ZEROS
#define MAX_ZEROS 8
#endif
#else /* not defined LONG_TEST */
#ifndef BUFF_SIZE
#define BUFF_SIZE 1024
#endif

#ifndef MAX_BLOCK_SIZE
#define MAX_BLOCK_SIZE 64
#endif

#ifndef MAX_OFFSET
#define MAX_OFFSET 3
#endif

#ifndef MAX_DIFF
#define MAX_DIFF 4
#endif

#ifndef MAX_LEN
#define MAX_LEN 4
#endif

#ifndef MAX_ZEROS
#define MAX_ZEROS 4
#endif
#endif /* not defined LONG_TEST */

#if (MAX_OFFSET >= 26)
#error "MAX_OFFSET >= 26"
#endif
#if (MAX_OFFSET + MAX_BLOCK_SIZE + MAX_DIFF + MAX_LEN + MAX_ZEROS >= BUFF_SIZE)
#error "Buffer overrun: MAX_OFFSET + MAX_BLOCK_SIZE + MAX_DIFF + MAX_LEN + MAX_ZEROS >= BUFF_SIZE."
#endif


#define TOO_MANY_ERRORS 11
int errors = 0;

const char *testname = "strcmp";

static void
print_error (char const* msg, ...)
{
  errors++;
  if (errors == TOO_MANY_ERRORS)
    {
      fprintf (stderr, "Too many errors.\n");
    }
  else if (errors < TOO_MANY_ERRORS)
    {
      va_list ap;
      va_start (ap, msg);
      vfprintf (stderr, msg, ap);
      va_end (ap);
    }
  else
    {
      /* Further errors omitted.  */
    }
}

#if 0
static void
printbuf (char *buf, char *name)
{
  int i;
  printf ("\n %s=", name);
  for (i = 0; i < BUFF_SIZE; i++)
    if (buf[i] != 0)
      printf ("(%d,%c)", i, buf[i]);
    else
      printf ("(%d,%s)", i, "\\0");
  printf ("\n");
}
#endif

int
main (void)
{
  /* Allocate buffers to read and write from.  */
  char src[BUFF_SIZE], dest[BUFF_SIZE];

  /* Fill the source buffer with non-null values, reproducable random data.  */
  srand (1539);
  unsigned i, j, zeros;
  unsigned sa;
  unsigned da;
  unsigned n, m, len;
  char *p;
  int ret;

  /* Make calls to strcmp with block sizes ranging between 1 and
     MAX_BLOCK_SIZE bytes, aligned and misaligned source and destination.  */
  for (sa = 0; sa <= MAX_OFFSET; sa++)
    for (da = 0; da <= MAX_OFFSET; da++)
      for (n = 1; n <= MAX_BLOCK_SIZE; n++)
	{
	for (m = 1;  m < n + MAX_DIFF; m++)
	  for (len = 0; len < MAX_LEN; len++)
	    for  (zeros = 1; zeros < MAX_ZEROS; zeros++)
	    {
	      if (n - m > MAX_DIFF)
		continue;
	      /* Make a copy of the source.  */
	      j = 'A';
	      for (i = 0; i < BUFF_SIZE; i++)
		{
		  src[i] = j;
		  if (j++ == 'Z') j = 'A';
		  dest[i] = src[i];
		}
	      memcpy (dest + da, src + sa, n);

	      /* Make src 0-terminated.  */
	      p = src + sa + n - 1;
	      for (i = 0; i < zeros; i++)
		{
		  *p++ = '\0';
		}

	      /* Modify dest.  */
	      p = dest + da + m - 1;
	      for (j = 0; j < len; j++)
		*p++ = 'x';
	      /* Make dest 0-terminated.  */
	      *p = '\0';

	      ret = strcmp (src + sa, dest + da);

	      /* Check return value.  */
	      if (n == m)
		{
		  if (len == 0)
		    {
		      if (ret != 0)
			{
			print_error ("\nFailed: after %s of %u bytes "
				     "with src_align %u and dst_align %u, "
				     "dest after %d bytes is modified for %d bytes, "
				     "return value is %d, expected 0.\n",
				     testname, n, sa, da, m, len, ret);
			}
		    }
		  else
		    {
		      if (ret >= 0)
			print_error ("\nFailed: after %s of %u bytes "
				     "with src_align %u and dst_align %u, "
				     "dest after %d bytes is modified for %d bytes, "
				     "return value is %d, expected negative.\n",
				     testname, n, sa, da, m, len, ret);
		    }
		}
	      else if (m > n)
		{
		  if (ret >= 0)
		    {
		      print_error ("\nFailed: after %s of %u bytes "
				   "with src_align %u and dst_align %u, "
				   "dest after %d bytes is modified for %d bytes, "
				   "return value is %d, expected negative.\n",
				   testname, n, sa, da, m, len, ret);
		    }
		}
	      else  /* m < n */
		{
		  if (len == 0)
		    {
		      if (ret <= 0)
			print_error ("\nFailed: after %s of %u bytes "
				     "with src_align %u and dst_align %u, "
				     "dest after %d bytes is modified for %d bytes, "
				     "return value is %d, expected positive.\n",
				     testname, n, sa, da, m, len, ret);
		    }
		  else
		    {
		      if (ret >= 0)
			print_error ("\nFailed: after %s of %u bytes "
				     "with src_align %u and dst_align %u, "
				     "dest after %d bytes is modified for %d bytes, "
				     "return value is %d, expected negative.\n",
				     testname, n, sa, da, m, len, ret);
		    }
		}
	    }
	}

  /* Check some corner cases.  */
  src[1] = 'A';
  dest[1] = 'A';
  src[2] = 'B';
  dest[2] = 'B';
  src[3] = 'C';
  dest[3] = 'C';
  src[4] = '\0';
  dest[4] = '\0';

  src[0] = 0xc1;
  dest[0] = 0x41;
  ret = strcmp (src, dest);
  if (ret <= 0)
    print_error ("\nFailed: expected positive, return %d\n", ret);

  src[0] = 0x01;
  dest[0] = 0x82;
  ret = strcmp (src, dest);
  if (ret >= 0)
    print_error ("\nFailed: expected negative, return %d\n", ret);

  dest[0] = src[0] = 'D';
  src[3] = 0xc1;
  dest[3] = 0x41;
  ret = strcmp (src, dest);
  if (ret <= 0)
    print_error ("\nFailed: expected positive, return %d\n", ret);

  src[3] = 0x01;
  dest[3] = 0x82;
  ret = strcmp (src, dest);
  if (ret >= 0)
    print_error ("\nFailed: expected negative, return %d\n", ret);

  printf ("\n");
  if (errors != 0)
    {
      printf ("ERROR. FAILED.\n");
      abort ();
    }
  exit (0);
}
